A serial killer is defined as an individual who murders two or more vi
ctims over an extended period of time, ranging from days to years, wit
h the crimes often being sexually motivated. Although there is a growi
ng popular emphasis on the phenomenon, there is a paucity of rigorous
research in the area. The present article reviews existing motivationa
l theories of serial murder and proposes additional explications from
a range of disciplines. Suggestions for future research are presented
and integrational approaches are encouraged.